Efficient and Robust Automotive Radar Coherent Integration With Range Migration

Conventional automotive radar perform range-Doppler coherent integration (stretch processing) under the assumption that the range of each object is constant during the integration interval. This assumption yields an efficient computation algorithm. However, when the object's relative speed is high and/or the coherent integration interval is large, the range migration is significant with respect to the range resolution, and as a result, the detection performance of the conventional range-Doppler coherent integration degrades significantly. The Radon-Fourier Transform (RFT) is the optimal method (in the sense of detection performance) for coherent integration with range migration, however, its complexity is large and may not be practical for implementation. In this paper, we develop a range-Doppler coherent integration algorithm that takes into account the range migration with efficient computation. We utilize the fact that range migration is a function of the Doppler frequency and derive an approximation to the RFT. The proposed algorithm significantly outperforms conventional coherent integration when the object's range migration is significant. Furthermore, it attains the performance of the RFT but with significantly lower complexity.